The present invention relates to a lens drive device including a polymer actuator element, and a lens module and an image pickup device provided with such a lens drive device.
In recent years, portable electronic devices such as mobile phones, personal computers (PCs), or PDAs (Personal Digital Assistants) have been remarkably improved in performance, and those having an imaging function with the provision of a lens module are now popular. In such portable electronic devices, focusing and zooming are performed by moving a lens in the lens module in the direction of an optical axis thereof.
Previously, for moving the lens in the lens module, generally used is a method therefor using a voice coil motor or a stepping motor as a drive section. However, in terms of size reduction, recently developed is the one using a polymer actuator element as a drive section (for example, see Patent Literatures 1 and 2). The polymer actuator element is the one including an ion-exchange resin film sandwiched between a pair of electrodes, for example. In this polymer actuator element, due to a potential difference between the pair of electrodes, the ion-exchange resin film is displaced in the direction orthogonal to the film surface.